This is not your typical jungle gym.

Chicago's Navy Pier on Lake Michigan was a training hub for aircraft carrier pilots during WWII.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

A display of magnificent stained glass windows is the first exhibit of its kind.

When you visit his grave, be sure to rub the Great Emancipator's nose for good luck.

The U.S. Supreme Court's secret Cold War relocation facility in the mountains of North Carolina.

A mailbox that saved a nature reserve.

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

An architect's childhood fantasy treehouse made real.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

A massive tribute to this small county's top agricultural product.

While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

There’s a hidden military meme engraved on the World War II Memorial.

The "lovely red Vega" of the legendary record-settling pilot.

The walls of the iconic dome are hollow and have a secret stairway.

This replica of the Greek structure is in the heart of Nashville.

One of the best places to see feral Colonial Spanish Mustangs in the United States.

Beautiful Gothic-inspired lighthouse stands out among the run-of-the-mill striped fare on Bodies Island.

This shifting North Carolina sand dune is an odd little desert surrounded by oceanic forest life.

Divinely-inspired village houses 6,000 dolls, plus strange and lovely outsider art.

Hidden behind Lincoln's head is a 70-foot-long chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

The first declared National Monument in the United States.

The twin towers in this Chicago fountain use 50 foot tall video screens to spit on people.